/*
    * Copyright (C) 2008 The Guava Authors
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    * http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.google.common.collect.testing.google;
  
  import static com.google.common.base.Preconditions.checkNotNull;
  import static com.google.common.collect.Lists.newArrayList;
  import static com.google.common.collect.Sets.newTreeSet;
  import static com.google.common.collect.testing.SampleElements.Strings.AFTER_LAST;
  import static com.google.common.collect.testing.SampleElements.Strings.AFTER_LAST_2;
  import static com.google.common.collect.testing.SampleElements.Strings.BEFORE_FIRST;
  import static com.google.common.collect.testing.SampleElements.Strings.BEFORE_FIRST_2;
  import static junit.framework.Assert.assertEquals;
  
  import com.google.common.annotations.GwtCompatible;
  import com.google.common.collect.ContiguousSet;
  import com.google.common.collect.DiscreteDomain;
  import com.google.common.collect.ImmutableSet;
  import com.google.common.collect.ImmutableSortedSet;
  import com.google.common.collect.Lists;
  import com.google.common.collect.Ordering;
  import com.google.common.collect.Range;
  import com.google.common.collect.Sets;
  import com.google.common.collect.testing.TestCollectionGenerator;
  import com.google.common.collect.testing.TestCollidingSetGenerator;
  import com.google.common.collect.testing.TestIntegerSortedSetGenerator;
  import com.google.common.collect.testing.TestSetGenerator;
  import com.google.common.collect.testing.TestStringListGenerator;
  import com.google.common.collect.testing.TestStringSetGenerator;
  import com.google.common.collect.testing.TestStringSortedSetGenerator;
  import com.google.common.collect.testing.TestUnhashableCollectionGenerator;
  import com.google.common.collect.testing.UnhashableObject;
  
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.Comparator;
  import java.util.List;
  import java.util.Set;
  import java.util.SortedSet;
  
  /**
   * Generators of different types of sets and derived collections from sets.
   *
   * @author Kevin Bourrillion
   * @author Jared Levy
   * @author Hayward Chan
   */
  @GwtCompatible(emulated = true)
  public class SetGenerators {
  
    public static class ImmutableSetCopyOfGenerator extends TestStringSetGenerator {
      @Override protected Set<String> create(String[] elements) {
        return ImmutableSet.copyOf(elements);
      }
    }
  
    public static class ImmutableSetWithBadHashesGenerator
        extends TestCollidingSetGenerator
        // Work around a GWT compiler bug.  Not explicitly listing this will
        // cause the createArray() method missing in the generated javascript.
        // TODO: Remove this once the GWT bug is fixed.
        implements TestCollectionGenerator<Object> {
      @Override
      public Set<Object> create(Object... elements) {
        return ImmutableSet.copyOf(elements);
      }
    }
  
    public static class DegeneratedImmutableSetGenerator
        extends TestStringSetGenerator {
      // Make sure we get what we think we're getting, or else this test
      // is pointless
      @SuppressWarnings("cast")
      @Override protected Set<String> create(String[] elements) {
        return (ImmutableSet<String>)
            ImmutableSet.of(elements[0], elements[0]);
      }
    }
  
    public static class ImmutableSortedSetCopyOfGenerator
        extends TestStringSortedSetGenerator {
      @Override protected SortedSet<String> create(String[] elements) {
        return ImmutableSortedSet.copyOf(elements);
      }
    }
  
   public static class ImmutableSortedSetHeadsetGenerator
       extends TestStringSortedSetGenerator {
     @Override protected SortedSet<String> create(String[] elements) {
       List<String> list = Lists.newArrayList(elements);
       list.add("zzz");
       return ImmutableSortedSet.copyOf(list)
           .headSet("zzy");
     }
   }
 
   public static class ImmutableSortedSetTailsetGenerator
       extends TestStringSortedSetGenerator {
     @Override protected SortedSet<String> create(String[] elements) {
       List<String> list = Lists.newArrayList(elements);
       list.add("\0");
       return ImmutableSortedSet.copyOf(list)
           .tailSet("\0\0");
     }
   }
 
   public static class ImmutableSortedSetSubsetGenerator
       extends TestStringSortedSetGenerator {
     @Override protected SortedSet<String> create(String[] elements) {
       List<String> list = Lists.newArrayList(elements);
       list.add("\0");
       list.add("zzz");
       return ImmutableSortedSet.copyOf(list)
           .subSet("\0\0", "zzy");
     }
   }
 
   public static class ImmutableSortedSetExplicitComparator
       extends TestStringSetGenerator {
 
     private static final Comparator<String> STRING_REVERSED
         = Collections.reverseOrder();
 
     @Override protected SortedSet<String> create(String[] elements) {
       return ImmutableSortedSet.orderedBy(STRING_REVERSED)
           .add(elements)
           .build();
     }
 
     @Override public List<String> order(List<String> insertionOrder) {
       Collections.sort(insertionOrder, Collections.reverseOrder());
       return insertionOrder;
     }
   }
 
   public static class ImmutableSortedSetExplicitSuperclassComparatorGenerator
       extends TestStringSetGenerator {
 
     private static final Comparator<Comparable<?>> COMPARABLE_REVERSED
         = Collections.reverseOrder();
 
     @Override protected SortedSet<String> create(String[] elements) {
       return new ImmutableSortedSet.Builder<String>(COMPARABLE_REVERSED)
           .add(elements)
           .build();
     }
 
     @Override public List<String> order(List<String> insertionOrder) {
       Collections.sort(insertionOrder, Collections.reverseOrder());
       return insertionOrder;
     }
   }
 
   public static class ImmutableSortedSetReversedOrderGenerator
       extends TestStringSetGenerator {
 
     @Override protected SortedSet<String> create(String[] elements) {
       return ImmutableSortedSet.<String>reverseOrder()
           .addAll(Arrays.asList(elements).iterator())
           .build();
     }
 
     @Override public List<String> order(List<String> insertionOrder) {
       Collections.sort(insertionOrder, Collections.reverseOrder());
       return insertionOrder;
     }
   }
 
   public static class ImmutableSortedSetUnhashableGenerator
       extends TestUnhashableSetGenerator {
     @Override public Set<UnhashableObject> create(
         UnhashableObject[] elements) {
       return ImmutableSortedSet.copyOf(elements);
     }
   }
 
   public static class ImmutableSetAsListGenerator
       extends TestStringListGenerator {
     @Override protected List<String> create(String[] elements) {
       return ImmutableSet.copyOf(elements).asList();
     }
   }
 
   public static class ImmutableSortedSetAsListGenerator
       extends TestStringListGenerator {
     @Override protected List<String> create(String[] elements) {
       Comparator<String> comparator = createExplicitComparator(elements);
       ImmutableSet<String> set = ImmutableSortedSet.copyOf(
           comparator, Arrays.asList(elements));
       return set.asList();
     }
   }
 
   public static class ImmutableSortedSetSubsetAsListGenerator
       extends TestStringListGenerator {
     @Override protected List<String> create(String[] elements) {
       Comparator<String> comparator = createExplicitComparator(elements);
       ImmutableSortedSet.Builder<String> builder
           = ImmutableSortedSet.orderedBy(comparator);
       builder.add(BEFORE_FIRST);
       builder.add(elements);
       builder.add(AFTER_LAST);
       return builder.build().subSet(BEFORE_FIRST_2,
           AFTER_LAST).asList();
     }
   }
 
   public static class ImmutableSortedSetAsListSubListGenerator
       extends TestStringListGenerator {
     @Override protected List<String> create(String[] elements) {
       Comparator<String> comparator = createExplicitComparator(elements);
       ImmutableSortedSet.Builder<String> builder
           = ImmutableSortedSet.orderedBy(comparator);
       builder.add(BEFORE_FIRST);
       builder.add(elements);
       builder.add(AFTER_LAST);
       return builder.build().asList().subList(1, elements.length + 1);
     }
   }
 
   public static class ImmutableSortedSetSubsetAsListSubListGenerator
       extends TestStringListGenerator {
     @Override protected List<String> create(String[] elements) {
       Comparator<String> comparator = createExplicitComparator(elements);
       ImmutableSortedSet.Builder<String> builder
           = ImmutableSortedSet.orderedBy(comparator);
       builder.add(BEFORE_FIRST);
       builder.add(BEFORE_FIRST_2);
       builder.add(elements);
       builder.add(AFTER_LAST);
       builder.add(AFTER_LAST_2);
       return builder.build().subSet(BEFORE_FIRST_2,
           AFTER_LAST_2)
               .asList().subList(1, elements.length + 1);
     }
   }
 
   public abstract static class TestUnhashableSetGenerator
       extends TestUnhashableCollectionGenerator<Set<UnhashableObject>>
       implements TestSetGenerator<UnhashableObject> {
   }
 
   private static Ordering<String> createExplicitComparator(
       String[] elements) {
     // Collapse equal elements, which Ordering.explicit() doesn't support, while
     // maintaining the ordering by first occurrence.
     Set<String> elementsPlus = Sets.newLinkedHashSet();
     elementsPlus.add(BEFORE_FIRST);
     elementsPlus.add(BEFORE_FIRST_2);
     elementsPlus.addAll(Arrays.asList(elements));
     elementsPlus.add(AFTER_LAST);
     elementsPlus.add(AFTER_LAST_2);
     return Ordering.explicit(Lists.newArrayList(elementsPlus));
   }
 
   /*
    * All the ContiguousSet generators below manually reject nulls here. In principle, we'd like to
    * defer that to Range, since it's ContiguousSet.create() that's used to create the sets. However,
    * that gets messy here, and we already have null tests for Range.
    */
 
   /*
    * These generators also rely on consecutive integer inputs (not necessarily in order, but no
    * holes).
    */
 
   // SetCreationTester has some tests that pass in duplicates. Dedup them.
   private static <E extends Comparable<? super E>> SortedSet<E> nullCheckedTreeSet(E[] elements) {
     SortedSet<E> set = newTreeSet();
     for (E element : elements) {
       // Explicit null check because TreeSet wrongly accepts add(null) when empty.
       set.add(checkNotNull(element));
     }
     return set;
   }
 
   public static class ContiguousSetGenerator extends AbstractContiguousSetGenerator {
     @Override protected SortedSet<Integer> create(Integer[] elements) {
       return checkedCreate(nullCheckedTreeSet(elements));
     }
   }
 
   public static class ContiguousSetHeadsetGenerator extends AbstractContiguousSetGenerator {
     @Override protected SortedSet<Integer> create(Integer[] elements) {
       SortedSet<Integer> set = nullCheckedTreeSet(elements);
       int tooHigh = (set.isEmpty()) ? 0 : set.last() + 1;
       set.add(tooHigh);
       return checkedCreate(set).headSet(tooHigh);
     }
   }
 
   public static class ContiguousSetTailsetGenerator extends AbstractContiguousSetGenerator {
     @Override protected SortedSet<Integer> create(Integer[] elements) {
       SortedSet<Integer> set = nullCheckedTreeSet(elements);
       int tooLow = (set.isEmpty()) ? 0 : set.first() - 1;
       set.add(tooLow);
       return checkedCreate(set).tailSet(tooLow + 1);
     }
   }
 
   public static class ContiguousSetSubsetGenerator extends AbstractContiguousSetGenerator {
     @Override protected SortedSet<Integer> create(Integer[] elements) {
       SortedSet<Integer> set = nullCheckedTreeSet(elements);
       if (set.isEmpty()) {
         /*
          * The (tooLow + 1, tooHigh) arguments below would be invalid because tooLow would be
          * greater than tooHigh.
          */
         return ContiguousSet.create(Range.openClosed(0, 1), DiscreteDomain.integers()).subSet(0, 1);
       }
       int tooHigh = set.last() + 1;
       int tooLow = set.first() - 1;
       set.add(tooHigh);
       set.add(tooLow);
       return checkedCreate(set).subSet(tooLow + 1, tooHigh);
     }
   }
 
   private abstract static class AbstractContiguousSetGenerator
       extends TestIntegerSortedSetGenerator {
     protected final ContiguousSet<Integer> checkedCreate(SortedSet<Integer> elementsSet) {
       List<Integer> elements = newArrayList(elementsSet);
       /*
        * A ContiguousSet can't have holes. If a test demands a hole, it should be changed so that it
        * doesn't need one, or it should be suppressed for ContiguousSet.
        */
       for (int i = 0; i < elements.size() - 1; i++) {
         assertEquals(elements.get(i) + 1, (int) elements.get(i + 1));
       }
       Range<Integer> range =
           (elements.isEmpty()) ? Range.closedOpen(0, 0) : Range.encloseAll(elements);
       return ContiguousSet.create(range, DiscreteDomain.integers());
     }
   }
 }